Fracturing can be accomplished using a series of valves that each have ball seats. The ball seats get progressively larger going uphole and progressively larger balls are launched or dropped to sequentially open the fracturing valves in a bottom up direction. As one zone is fractured the next ball isolates the already fractured zone and opens the next valve going in an uphole direction. The problem with this system is there is a limit to how many balls of different sizes can be accommodated in a borehole of a given size. Another problem is that the balls have such small size difference to accommodate as many zones as possible that surface personnel can inadvertently grab the wrong ball. Organizers for such ball arrays are shown in U.S. Pat. No. 8,157,090. Despite the use of organizers to keep track the wrong ball can still be inadvertently picked.
One offered solution to the progressively larger ball seats in a bottom up fracturing operation has been offered in U.S. Pat. No. 7,322,417. Here the same ball is used and all but the initial ball seat are retracted. Once the first ball lands and opens a fracturing valve, it also extends the next ball seat up to accept the same size ball. Here the offered advantage is that all the balls are the same size. The limitations are that the actuation order is still fixed from bottom up and the mechanism that connects the shifting of one ball seat to the extension of a ball seat above can be quite complex and expensive to build or operate.
Also relevant are U.S. Pat. No. 7,552,779 and U.S. Pat. No. 7,325,617; U.S. Pat. No. 4,823,882; U.S. Pat. No. 7,377,321; U.S. Pat. No. 8,356,670; U.S. Pat. No. 8,701,776; U.S. Pat. No. 9,004,180; U.S. Pat. No. 9,004,179; U.S. Pat. No. 8,616,285; U.S. Pat. No. 8,863,853; U.S. Pat. No. 8,479,823; U.S. Pat. No. 8,668,013; U.S. Pat. No. 8,789,600; U.S. Pat. No. 8,261,761; U.S. Pat. No. 8,291,988; U.S. Pat. No. 8,397,823; U.S. Pat. No. 8,646,531 and U.S. Pat. No. 8,770,299).
The present invention seeks to optimize a fracturing operation by using intelligent objects such as balls or darts that keep track of how many valve assemblies have been passed by the object so that the mechanism of the object can be reconfigured at the desired valve for latching and ultimately shifting the valve with applied pressure in the borehole. These and other aspects of the present invention will be more readily apparent to those skilled in the art from a review of the detailed description of the preferred embodiment and the associated drawings while recognizing that the full scope of the invention can be determined from the appended claims.